Threading tool grinding fixture



Aug. 31, 1948. R. F. GRIECO 2,448,309

THREADING TOOL GRINDING FIXTURE Filed June 12, 1945 Rocco F Gn'ecoINVENTOR.

BY @waofiu MJMWMWS Patented Aug. 31, 1948 UNITED STATES PATENT OFFlCETHREADING TOOL GRINDING FIXTURE Rocco F. Grieco, Millburn, N. J.

Application June 12, 1945, Serial No. 599,022

4 Claims. 1

This invention relates to threading tools and has for its object toprovide means for holding a threading tool bit in exact position forgrinding the same for precision work.

Another object of the invention is to provide a tool holder having atilting table and means for indicating the exact angle at which a toolis to be ground.

A further object of the invention is to provide a bit holder arranged tohold the bit in precise position for grinding the same to cut threadsfor V-sharp, standard (60) and Acme (29), on a surface or other grindingmachine which would give the same result.

Other features and advantages will become more readily apparent from thefollowing description and the accompanying illustrative drawings inwhich:

Figure 1 is a perspective view of one form of the invention;

Figure 2 is a sectional view of the device shown in Figure 1;

Figure 3 is an elevational view showing the device in Figure 1 in anadjusted position;

Figure 4 is a diagrammatic elevational view indicating varying angles oftool clamp adjustment; and

Figure 5 is a fragmentary sectional view illustrating a second form ofthe invention.

The first form of the invention generally indicated at l2 may be seenbest in Figures 1 and 2. A substantially fiat base I3 is provided withbearing brackets I 4 and I5, respectively. The said brackets l4 and I5are attached by any suitable conventional means such as the screwsillustrated.

Fixedly mounted in the bearing brackets 14 and I5, respectively, is apintle l6, upon which a bearing block I! is pivotally secured. The saidbearing block I! is preferably secured to the pintle through the utilityof a pair of jaws l8 and 19 formed by slitting the block at its lowerend and reaming the block to form bearings for engagement with the saidpintle I 6.

The tilting block I! is so slit as to permit a slight resiliency betweenthe jaws l8 and I9 whereby, through the medium of the tension screw 23,the jaws may be caused to fixedly grip the said pintle 16. Of course,the screw 23 extends through the jaws and I9 and also is anchoredfixedly (relative to the other jaw) through the medium of screw threads.

A bore 25 is formed in the upper end of the block I1 and a collar 26 isrotatably mounted therein. Extending within the central bore of the saidcollar 26 is a pivot member 28 having jaws 29 and 30 associatedtherewith. A screw 21 is countersunk in the collar 26 and threadedlysecured to the said pivot member 2%.

The said jaws 29 and 30 are so spaced as to accommodate a shank 3! whichis a portion of a tool. Set screws 33 and 34 may be provided in the saidjaw 30 for frictional engagement with the shank 3|, in anchoring thesame.

One rim 36 of the said collar 26 is exposed to view on one surface ofthe said block ll. Suitable indicia are supplied on the said exposed rim38 for cooperation with complemental indicia on the tilting block l1. Byturning the said collar 26 (using the bit or tool 31 as a crank), inorder to bring the indicia into alignment with the complemental indicia,the tool may be brought to any desired angle relative to a grindingwheel 35 (see Fig. 3).

Inspection of Figure 1 discloses indicia on the bearing bracket l5 whichis cooperative with suitable indicia on one edge of the said tiltingblock l1. Through utility of this indicia, the block I! may be tilted toa desired, known angle in bringing the end of the tool 3| to apredetermined position relative to the grinder 35. p

A bore or other suitable aperture id may be supplied in the base 63 inorder to clampingly engage the said base in a desired position relativeto a table or other suitable datum to perform specific cuttingoperations.

The clearance of a thread-cutting bit (front or side clearance) may bedetermined by the diameter and pitch of a screw to be out, whichclearance is obtained by the position of the tilting block H, whichtakes its angular reading from the indicia generally indicated at it.The angle of the thread cutter bit may be obtained by the rotaryadjustment of bit 3! about the axis of collar 26.

Referring now primarily to Figure 2, the first form of the invention isillustrated in detail.

This species of the invention illustrates the first means for fixing thecollar 25 in a set position. The said collar 26 is provided with aplurality of notches 54 about the periphery thereof which notches arecooperative with a pin 53.

The said split tilting block H is provided with a bore 50 extendingaxially thereof. The said bore 50 also accommodates a pin 53 whichcooperates with the said notches 5 i as mentioned above. Further, thecounterbore 22 which is provided substantially parallel to thebearingforming bore on the said pintle l8 communicates with the slit inthe tilting block ll. A spring 22 seats on the said screw 23 and bearsagainst the said pin 53, normally urging the same into operativeengagement with the periphery of the said collar 26. Of course, themachined edge of the said pin 53 is adapted to seat in the said notches50. which are of complemental shape. Through this expedient, the collar26 may be held against rotation relative to the tilting block ll.

The said pin 53 is provided with an arm 60 which is operative in a slot62. The said slot is formed in the said tilting block 11 (see Fig. 2) inorder to limit the travel of the said pin. A rod 64 is pivoted to theouter surface of the said tilting block I! through the medium of aconven-' tional screw or the like 68. This rod also has the arm E50secured thereto, whereby, upon actuation of the rod 84, the pin 50 willbe selectively.

raised and resiliently returned.

Referring now to the embodiment of the invention shown in Figure 5, itwill be seen that a pin '12 is supplied in the bore 14. Of course, thecollar 25 is identical in this species as is the plurality of notches54. The said pin 12 is adapted to seat in selective notches 54 forlocking purposes. An arm '16 is secured to the said pin 12 and isnormally resiliently biased'by means of a spring 18. The said springseats on the said pin 12 as well as the adjustable andremovable-apertured plug 89. The said plug is threadedly received in thebore 82 formed in the said tilting block I! and an actuation knob may beassociated with the arm 16.

Minor changes in shape, size and rearrangement of details may, ofcourse, be resorted to without departing from the spirit of theinvention.

That which I claim as new in my invention is:

1. In a device of the nature described a flat hingedly mounted blockhaving a bore therethrough, a collar rotatably mounted through the bore,notches in the periphery of said collar, a scale on the face of theblock and indicia on the free edge of the collar cooperating therewithfor accuracy of adjustment, means for holding the collar in adjustedposition, comprising a second bore in said block, a resiliently biasedpin in said bore adapted to engage selective notches thereof, a rodsecured to said pin for actuation thereof, a fiat base upon which theblock is hinged, said block adapted to lie horizontally upon the base, apintle mounted upon the base, said block being split at its hinged endthroughout its Width to form jaws to clamp upon said pintle, means forsecuring said jaws in fixed position upon the pintle, and means in saidbase for receiving the last means in order that the block may lie flaton the base.

2. In a device of the nature described a flat hingedly mounted blockhaving a bore therethrough, a collar rotatably mounted through the bore,adapted to receive a tool therein, notches about the periphery of saidcollar, a scale on the face of the block and indicia on the free edge ofthe collar cooperating therewith for accuracy of adjustment, means jorholding the collar in adjusted position, including a resiliently biasedpin adapted to engage selective of said notches, a rod secured to saidpin for manual actuation thereof, a flat base upon which the block ishinged, said block adapted to lie horizontally upon the base, a pintlemounted upon the base, said block being split at its hinged endthroughout its width to form jaws to clamp upon said pintle, and meansfor securing said jaws in fixed position upon the pintle.

3. In a device of the nature described a flat hingedly mounted blockhaving a bore there "through, a collar rotatably mounted through thebore, notches in said collar, a scale on the face of the block andindicia on the free edge of the collar cooperating therewith foraccuracy of adjustment, means for holding the collar inadju'stedpositi'on, including a second bore in said block, 'aresiliently biased pin in said bore and manual means for urging said pinto selective notches in said collar, a fiat base upon which the block ishinged, said block adapted to lie horizontally upon the base, and apintle mounted upon the base, said block being split at its hinged endthroughout its width to form jaws to clamp upon said pintle.

4. A tool holder device comprising in combination a base plate adaptedfor locationin a h0rizontal plane, a block hingedly mounted at one endon said base plate for rotation about the hinge axis above the baseplate, said block having opposite flat sides, means to secure the saidblock in any desired position of rotation about the hinge axis, a boreopening through the block between the opposite flat sides thereof, saidopening being located adjacent the upper end thereof, a collar rotatablymounted in said bore opening and means securing the collar selectivelyin any one of a few predetermined positions of rotation therein, a toolholder having a tubular extension thereon seating Within said collar tobe rotatable therein and means securing said tool holder to the saidcollar in any desired position of rotation therein.

ROCCO F. GRIECO.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 522,155 Dooley June 26, 18941,377,884 Heryngfel et al. May 10,1921 1,385,519 Calhoun July 26, 19211,807,999 McMurtry June 2, 1931 1,889,248 Kilmer Nov. 29, 1932 1,915,247Holloway et al June 20, 1933 FOREIGN PATENTS Number Country Date 349,576Germany Mar. 6, 1922

